Actually there is a large contingent of aquarium hobbyists / plant growers in Seattle. Our local club, the Greater Seattle Aquarium Society is over 40 years old and when there isn't a COVID-19 thing going on we meet monthly at Seattle Pacific University. Since the virus we have been having Zoom meetings (with speakers) once a month. Check us out at: https://gsas.org
We also have three FB pages, an 'open' once for announcements to the public and two closed ones. One is a 'Buying and Selling' FB page and the other is for sharing aquarium hobby stuff.